OAKLAND — For 1,100 miles, the California coast threads like a ribbon past one of the most varied landscapes in the United States — farmland, airports, beach fronts, high-tech startups, forest and cargo ships with a 50-foot draft chugging past on the way to the Port of Oakland.

But the shoreline and the bay are changing and could change even more if predictions of climbing sea levels — 16 inches by midcentury — and flooding turn into reality.

Even a modest rise could make flooding more common by adding to tides and storm surges, according to experts.

San Mateo County, sitting on 240 miles of landfill, is the most at-risk among its Northern California neighbors if sea levels rise from 1 to 10 feet, according to the National Oceanic and Atmospheric Administration. Alameda, Santa Clara, Contra Costa, Marin and Sacramento counties are close behind.

The question is how to prepare for the scenario of rising waters and storm surges while navigating competing uses, regulations, agendas and visions for what the future should hold for the Bay Area shoreline and the people who live in its orbit.

“We want it all but there are trade-offs,” State Lands Commission Executive Director Jennifer Lucchesi said. Her agency oversees the use of tidal and submerged lands such as Jack London Square. “There’s a balancing act that has to go on,” Lucchesi said Friday at the Decision Makers Conference in Oakland.

The annual conference, organized by the Bay Planning Coalition, gathered leaders from the private and public sectors to discuss striking a balance between a thriving economy and planning for climate change without bogging down the already complex, slow process of waterfront development.

The friction over the future was on display in March when Port of Oakland commissioners rejected a trio of bids for maritime uses at Howard Terminal — one involving coal shipping — in favor of a baseball park plan.

A waterfront ballpark would seem like the perfect fit for an outmoded terminal near Jack London Square and a port that recognizes the need to modernize. Instead, the decision added to the conflict over how the berths should be used. The area’s industrial businesses see a threat of being pushed out by condos, restaurants and baseball fans.

“Some people don’t want heavy industry even though it produces good-paying jobs,” said John Coleman, executive director of the Bay Planning Coalition, which represents the maritime industry and related stakeholders.

“Industry has a place on the bay but obviously there is overcapacity,” said Mike Ghielmetti, a member of the group behind the Howard Terminal ballpark plan, Oakland Waterfront Ballpark LLC. His mixed housing and retail Brooklyn Basin project on 65 empty and rusting acres is one example of how the modern economy and changes to the maritime industry have changed the waterfront.

The project broke ground recently after 13 years and a web of regulations involving nine agencies, including the State Lands Commission, Bay Conservation and Development Commission and Army Corps of Engineers. “We can aspire to a rigorous process but one that is less complex,” said Ghielmetti, president of Signature Development. “It takes a long time and it shouldn’t.”

The Golden State Warriors experienced the dynamics of waterfront development while pursuing an arena at Piers 30-32 in San Francisco. The Warriors would have had to raise the pier to address the climb in sea levels, costing more than $100 million, if they had not abandoned plans for the site after a battle erupted over a measure to limit height limits on waterfront high-rise hotels and condos. The team instead reached a deal for a Mission Bay property. The measure would also affect the Giants’ plans to build on a parking lot as well as the repurposing of the old Union Iron Works at Pier 70 in San Francisco with space for offices, light industry and artists.

Building on the water is “a very arduous process and a very, very challenging thing to do,” Warriors owner Ricks Welts told the audience of more than 320 industry, scientific and government leaders at the conference.

The agencies’ involvement dates back to the 1960s, when development had consumed a third of the Bay and nearly all of the tidal marshes. The Bay Area today has inherited 150 years worth of changes, from dredging for shipping channels to dikes that turned wetlands into lagoon communities like Foster City — a town fabricated atop marshes with landfill and surrounded by levees — and agricultural land into Silicon Valley. Downtown San Jose is several feet below sea level and San Francisco’s financial district was once mud flats. Oracle has a threat management center that plans for risks like storm surges.

Laws are still evolving on the local, state and federal level. The Bay Conservation and Development Commission, a state agency, passed the first regulations to require developers to consider sea level rise on projects along San Francisco Bay’s shoreline, with intense pushback from the business community.

Howard Terminal, the Warriors’ new Mission Bay arena site and the last four major developments approved in Oakland — Brooklyn Basin, the Army Base, Jack London Square and the Martin Luther King Jr. Regional Shoreline — are all on or near the waterfront.

Research and a 7-inch climb in the bay water levels since 1900 are convincing decision-makers that without intervention the Bay Area faces the scenario of rising waters washing over levees, crippling BART, highways, airports, wastewater treatment plants and even the Giants’ AT&T park. The area’s dual financial powerhouses — Central Valley farmlands and the Port of Oakland, together responsible for well over $50 billion in revenue and 100,000 jobs — would be maimed.

The severity of those predictions could prove wrong. But it’s a gamble investors and insurers are not going to take, said former California Insurance Commissioner, Rep. John Garamendi, D-Walnut Grove. In other words, they are unlikely to put up money for risky waterfront assets.

In the end, residents and cities carry the future burden, said David Lewis, executive director of Save the Bay.

“If it doesn’t pencil out,” ¿he said, “maybe it shouldn’t be there at all.”

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